fixup! Update lint documentation to use markdown headlines

clippy_lints/src/self_named_constructor.rs

@@ -6,14 +6,13 @@ use rustc_lint::{LateContext, LateLintPass};
 use rustc_session::{declare_lint_pass, declare_tool_lint};
 
 declare_clippy_lint! {
-    /// **What it does:** Warns when constructors have the same name as their types.
+    /// ### What it does
+    /// Warns when constructors have the same name as their types.
     ///
-    /// **Why is this bad?** Repeating the name of the type is redundant.
-    ///
-    /// **Known problems:** None.
-    ///
-    /// **Example:**
+    /// ### Why is this bad?
+    /// Repeating the name of the type is redundant.
     ///
+    /// ### Example
     /// ```rust,ignore
     /// struct Foo {}
     ///